The Solvents Recovery Service of New England (SRSNE) site located in the Town of Southington, Hartford County, Connecticut. The Site, which encompasses the former Operations Area (4 acres, fenced) and a groundwater plume, is approximately 42 acres. The facility operated as an EPA-approved hazardous waste treatment and storage facility. The facility received various waste industrial solvents that were blended for use as a fuel product. From 1957 to 1967, stillbottom sludges were disposed of in two unlined lagoons. In 1967, sludge disposal was discontinued, and the lagoons were drained and covered with fill. After the lagoons were closed, wastes were burned in an open pit on site or disposed of off site. In the 1970s, the State ordered that the incineration practice be discontinued. Past operating practices, spills, and poor housekeeping are sources of contamination. In 1991, all activities at the site ceased in preparation for closure under the Resource Conservation and Recovery Act (RCRA). No hazardous waste disposal currently takes place at the site. The Town of Southington Well #4 is located approximately 2,000 feet south of the site, and Well #6 is located 1,300 feet to the south of the site. Both of these wells were closed in 1979 because of contamination. The population of Southington is 38,000. The area near the site is a mixture of commercial, light industrial, residential, and some agricultural uses. The facility is located approximately 500 feet to the west of the Quinnipiac River.

The groundwater is contaminated with isopropyl alcohol, acetone, toluene, and other volatile organic compounds (VOCs). The soil is contaminated with lead, cadmium, polychlorinated biphenyls (PCBs), and VOCs. People who accidentally ingest contaminated groundwater may be at risk. However, since the two municipal wells have been taken out of service, this health threat has been reduced. Both dense non-aqueous phased liquids (DNAPLs) and light non-aqueous phased liquids (LNAPLs) have been identified at the site.

In 1983, EPA settled a lawsuit filed against SRSNE in 1979 under the authority of the Resource Conservation and Recovery Act (RCRA). Under the settlement, SRSNE was required to make improvements to its solvents handling procedures; construct a groundwater pump and treatment system to prevent the migration of overburden contaminated groundwater; and install an off-site interceptor system to capture contaminated groundwater beyond the facility boundaries. In 1985, SRSNE installed the on-site groundwater pump and treat system, and began operating it in 1986. The off-site interceptor system was also installed, though this system never became operational because SRSNE was never issued a discharge permit by the State of Connecticut. SRSNE also paved the operations area with asphalt, installed berms to contain spills, improved fire protection and suppression measures by extending the public water supply line to the facility and improved general housekeeping measures to some degree. Despite these efforts, numerous deficiencies remained.

Groundwater

In 1983, SRSNE constructed a groundwater pump and treatment system to address contaminated groundwater in the overburden, as required by the RCRA settlement. In 1995, the potentially responsible parties, under EPA oversight, installed a slurry wall and a more up-to-date groundwater pump and treatment system that consists of ultraviolet/oxidation to clean up shallow groundwater and prevent it from migrating from the source areas. In 1997, the EPA ordered the potentially responsible parties to expand the groundwater containment system to address bedrock contamination. The overburden and bedrock groundwater containment and on-site treatment systems were incorporated into the final remedy selected for the site in the September 2005 Record of Decision (ROD).

Soil

In 1992, EPA conducted a time-critical removal action to address potential health threats associated with PCB contamination in soil and sediment along a drainage ditch on the eastern edge of the operations area. Approximately 19 drums of contaminated material containing up to 100 parts per million (ppm) total VOCs and 350 ppm PCBs were removed. In 1994, the EPA conducted an investigation into the sources and nature and extent of contamination at the site. Subsequent information indicated that the investigation was not complete, and the potentially responsible parties completed the investigation under EPA oversight. A final remedy for the site, including soil, was selected in the ROD in September 2005.

Laboratory Chemicals and Asbestos

In 1994, EPA conducted a second time-critical removal action to remove and dispose of laboratory chemicals and asbestos that SRSNE had left at the abandoned site.

Non-aqueous Phase Liquid

Dense non-aqueous phase liquid (DNAPL) is located in the overburden and bedrock aquifers. Light non-aqueous phase liquid (LNAPL) is also in the overburden aquifer. Both DNAPL and LNAPL are addressed in the final remedy for the site in the September 2005 ROD.

Final Remedy for the Site

In May 2005, EPA proposed a final remedy for the site. EPA accepted public comment on its preferred alternative from June 9 thru August 8, 2005. After careful consideration of all written and verbal comments received during the comment period, EPA selectedthe following cleanup plan for the site:
* Treat waste oils and solvents in the overburden aquifer beneath the Operations Area by heating them in place.

* Consolidate and cap contaminated soil and wetland soil.

* Capture and treat on site the contaminated groundwater in both the overburden and bedrock aquifers that exceeds federal drinking water standards. Monitor natural degradation of the plume outside the capture zone until groundwater cleanup levels are achieved.

* Monitor natural degradation of the waste oils and solvents in the bedrock aquifer.

* Implement restrictions on uses of the site property and groundwater.

* Monitor groundwater and maintain the cap in the long term. Perform reviews at least every five years to ensure that the remedy remains protective of human health and the environment.

First Five-Year Review

EPA conducted the first five-year review of the remedy in 2010. Based upon a review of the ROD, remedial design documents, data collected during sampling events, operation and maintenance records, and a site inspection on June 2, 2010, EPA made the determination that the remedy at the SRSNE Site is expected to be protective of human health and the environment upon completion of the remedy, and in the interim, exposure pathways that could result in unacceptable risks are being controlled.

Open House July 2010

On July 10, 2010, EPA, CTDEEP and the SRSNE Site Group (an unincorporated association of Settling Defendants who are performing the remedy under agency oversight), hosted an open house for the public to learn about the upcoming remedial activities. Posters from the open house are posted at www.srsnesite.com (a website developed and maintained by the SRSNE Site Group).

Enforcement Highlights

In 1983, Solvents Recovery Service of New England (SRSNE) signed a Consent Decree with the EPA requiring the installation of a system to recover groundwater on and off site and a plan for on-site storage and management of hazardous wastes. Some of these actions were completed before SRSNE ceased operation in 1991. The EPA signed a final Consent Decree with SRSNE for settlement of its liabilities with respect to the site in early 1994. In addition, the EPA signed a Consent Decree with approximately 880 small potentially responsible parties for release of their liability for the site in late 1994. Approximately 250 parties signed an Administrative Order with EPA in 1994 to construct the groundwater pump and treat system and in 1996, approximately 500 parties signed an Administrative Order to expand the system and complete site investigations. In 2008, EPA entered into a Consent Decree with 59 parties ("SRSNE Site Group") who agreed to perform the site-wide cleanup, and pay past and future oversight and response costs. In 2008, EPA also entered into a Consent Decree with 213 "de minimis" parties who are settling their potential liability for cleanup costs by making cash payments. Settlements with various parties that have limited financial ability are completed or planned.

The closure of the contaminated drinking well has minimized the threat of exposure to affected residences while groundwater pump and treat operations continue at the Solvents Recovery Service of New England site. Contaminated groundwater in both the overburden and bedrock aquifers is being contained and treated on site. The ROD, issued in September 2005, is the final remedy for groundwater and contaminated soil.

Entry of the Consent Decree by the United States District Court for the District of Connecticut in March 2009 triggered the start of remedial design activities. Several activities have already been completed including the delineation of NAPL the overburden in the northwest corner of the Operations Area; a baseline habitat survey; new groundwater monitoring well installation; and groundwater sampling. Preparation of the site for in-situ thermal treatment is currently ongoing and includes significant earthworks; installation of thermal infrastructure (new gas, sewer, power); re-routing of a major AT&T optics line; and removing and replacing a leaky concrete culvert that runs across the site to the Quinnipiac River. This work is expected to be completed in fall 2012. Heater well installation for the in-situ thermal treatment will begin once that work is complete and will take several months. Start up of the thermal treatment is anticipated for late 2013/early 2014, and will take approximately 200 days.